1. Field of the Invention
This invention generally relates to circuit interrupter apparatus and, more particularly, to an improved vacuum type circuit breaker having an attached heat exchanger assembly which cools and thus prevents the contacts and associated current-carrying parts of the breaker from overheating during closed-circuit operation.
2. Description of the Prior Art
It is customary in the vacuum circuit breaker art to provide some means of cooling the current-carrying parts of the circuit breaker to prevent excessive temperature rises which may be produced by the passage of current through the breaker and result in overheating which could damage the breaker and/or interfere with its normal operation. In conventional vacuum type circuit breakers having current-carrying conductors of the solid bar type such cooling means comprises one or more extruded metal components of finned construction that are fastened to the solid-bar conductors and function as heat exchangers. However, it is impractical to employ such cooling components in vacuum circuit breakers having current-carrying conductors that consist of a plurality of bundled leaf-like conductor elements that provide "stiff flexible" type conductor assemblies since there is no convenient location along the flexible conductor assemblies where a finned cooling component can be attached. A circuit breaker having such a "stiff flexible" leaf conductor assembly that is connected to the movable contact stem of a vacuum type circuit breaker is disclosed and claimed in U.S. Pat. No. 4,384,179 issued May 17, 1983 to S. A. Milianowicz, the author of the present invention. The use of such a leaf conductor assembly on the stationary end of the circuit breaker as well as the movable end provides an improved circuit breaker structure and it is this type of circuit breaker which presented the problem that is addressed by the present invention.
The provision of an inexpensive heat exchanging assembly that can be easily manufactured and then mounted directly on such an improved vacuum circuit breaker having the aforementioned "stiff flexible" bundled leaf-like conductor assemblies to efficiently cool the current-carrying parts of the breaker would accordingly be advantageous from both a functional and cost standpoint.